Merge pull request #32 from max-schaefer/update-data-flow

Port recent data-flow improvements

ql/src/semmle/go/dataflow/internal/DataFlowPrivate.qll

@@ -1,6 +1,6 @@
 private import go
 private import DataFlowUtil
-private import DataFlowImplCommon::Public
+private import DataFlowImplCommon
 
 private newtype TReturnKind =
   TSingleReturn() or
@@ -270,3 +270,5 @@ predicate isUnreachableInCall(Node n, DataFlowCall call) {
     guard.dominates(n.getBasicBlock())
   )
 }
+
+int accessPathLimit() { result = 5 }

ql/src/semmle/go/dataflow/internal/DataFlowUtil.qll

@@ -283,11 +283,10 @@ class CallNode extends ExprNode {
     exists(DataFlow::Node calleeSource | calleeSource = getACalleeSource() |
       result = calleeSource.asExpr()
       or
-      exists(Method m, InterfaceType declaredRecv, Type actualRecv |
-        calleeSource = m.getARead() and
-        declaredRecv = m.getReceiverType().(NamedType).getBaseType() and
-        actualRecv.implements(declaredRecv) and
-        result = actualRecv.getMethod(m.getName()).(DeclaredFunction).getFuncDecl()
+      exists(Method declared, Method actual |
+        calleeSource = declared.getARead() and
+        actual.implements(declared) and
+        result = actual.(DeclaredFunction).getFuncDecl()
       )
     )
   }

ql/test/library-tests/semmle/go/dataflow/CallGraph/main.go

@@ -33,3 +33,7 @@ func test(x *s1, y s2, z s3, b mybool, i I) {
 	id := func(x int) int { return x } // name: id
 	id(1)                              // callee: id
 }
+
+func test2(v interface{}) {
+	v.(interface{ m(int) }).m(0)       // callee: s3.m
+}